[Radiance-general] Radiance

[Greg Ward]

Hello Brajesh,

I second Rob's motion that you check out the HDRI mailing list.   
Archives can be found at radiance-online.  I also recommend you  
download and try out Photosphere if you have a Mac available to you,  
as it does exactly what you want to do.

The following might also be of some use:

	http://radsite.lbl.gov/radiance/refer/Notes/filmspeed.html

Best,
-Greg

> From: "Guglielmetti, Robert" <Robert.Guglielmetti at nrel.gov>
> Date: July 1, 2009 8:11:18 AM PDT
> I’m not sure what you mean by the “radiance scale factor”. Are you  
> trying to compute the cameras’ response curves? As for your second  
> question, you won’t be able to calculate radiance from a single  
> exposure, even if all the details about that exposure are known.  
> The process you are describing requires a high dynamic range (HDR)  
> image, which is comprised of multiple exposures. The typical  
> minimum is three exposures separated by 2 f-stops each, but ideally  
> the longest exposure should have zero black pixels and the shortest  
> have no white pixels. This ideal is only necessary to capture  
> scenes of extreme dynamic range, however.
>
> Radiance-online.org also hosts an hdr mailing list which is  
> definitely worth subscribing to:
>
> http://www.radiance-online.org/mailman/listinfo/hdri
>
> Robert Guglielmetti  IES, LEED AP
>
>
>
> From: radiance-general-bounces at radiance-online.org [mailto:radiance- 
> general-bounces at radiance-online.org] On Behalf Of Brajesh Lal
> Sent: Wednesday, July 01, 2009 7:55 AM
>
> Hi All,
>
> I have taken images of same scene from two different camera at same  
> time and same day. How to find the radiance scale factor between  
> the two cameras.
>
> I will be grateful if somebody can explain me mathematical relation  
> to compute the radiance of a  point in the scene.
>
> if the pixel value of the point  and cameras ISO value, F-stop,  
> Shutter Speed are known
>
>
>
> Best Regards,
>
> Brajesh Lal
>
>